Antioxidant for rubber composition



Patented May 30, 1939 2,160,200

TED NT OFFICE .ANZDIOXIDANT IFOR RUBBER COMPOSITION Raymond 'F.'Dunbrook and Bingham 'J. Humphrey, Akron, Ohio, assignors toThe'Firestone Tire & Rubber Company, Akron, Ohio, a-corporation of OhioNo Drawing. Application December 21, 1936, Serial No.11'7,0.0 6

8 Claims. (01. 18 -50 This invention relates especially to impovedtested by compounding it in arubber mix and --age-r.esisting rubbercompositions and to methcomparing the resultant product with a controlodsiofmaking-thesame. consisting of the same ingredients'with the ex-.The invention is'of primary utilityin the man ception of the improvedantioxidant, which was ,5 ufacture :of carbon black rubberstocks, suchas omitted. The composition of the mixes was as ,5

tire tread stocks, thatare subject to light, heat, follows: oxidation,abrasion, flexing, and other destructive agencies during use.

The chief objects of the invention are to pro- A B vide an improvedmaterial suitable for incorpor- Withim- I 10 ating in oxidizable organiccompositions to re- Omltml Y v antioxidant tard deter1orat1on thereof;to improve the resistance of rubber to abrasion; and to check or PartsPam retard the formation of cracks in carbon black Smoked sheet 100 =10rubber stocks. Other objects will be manifest as Sul h g g 5 thespecification proceeds. 45 45 This invention consists in theincorporation in stearic acid g 3 rubber or like organic materials, ofan anti-ox- Mercapto-benzo-thiazolc 1.25 1.25

Antioxidant 0 1 idant or age-retarding compound of the general 0 classof dihydroquinolines represented by the general formula The respectivestocks A and B were thoroughly H mixed and then vulcanized in a pressfor 100, 120, )K Q 140 and 160 minutes at 264 F. Test strips were G6 0son cut from the vulcanized stocks and artificially 25 i aged, bothstocks being aged 14 days in the Geer c7 0 20 even at 70 C. and somebeing aged 46 hours in 3 the Bierer-Davis oxygen bomb at 70 C. The re- Hsults of these tests follow:

Normal data wherein the R in the 2 and 4 positions is an alkyl groupsuch as methyl, ethyl, propyl, isopropyl, butyl, etc., and the R. in the6 position is an aryl group such as a phenyl, tolyl, xylyl, etc. Formula35 An illustrative example of said general class is 160 the compound2,2,4-trimethyl-6 phenyl-l,2-di- Modulus at 400% Tensile at break A 27252000 3050 3100 4550 4550 4575 4400 y r q d f the followmg formula B 27002850 2975 3050 4600 4600 4575 4525 CH: Aged 14 days m Geer oven at C.

Hi0- CH CH:

M ul 04007 T 11 tb k 0d use a ens'ea rea 45 g CHa Formula 45 Thecompound is in the form of White crystals A 3025 3075 3350 3325 33253500 3050 3570 having a melting point of 5 B 3275 3450 3525 3075 40004175 4025 4100 50 The foregoing example of the compound was Aged 46hours in oxygen bomb The foregoing data clearly show that rubbercomposition comprising the improved antioxidant compares favorably withuntreated rubber stock in normal condition, and after artificial agingshows superior modulus and tensile characteristics.

Although but a single embodiment of the invention has been disclosed, itis not intended that the invention be limited solely thereto, since theexact proportions of the constituent materials may be varied, and othermaterials having equivalent chemical properties may be employed, ifdesired, without departing from the spirit of the invention or the scopeof the appended claims.

What is claimed is:

1. The method of retarding the deterioration of rubber which comprisestreating the rubber with 2,2,4-trimethyl-6 phenyl-1-,2-dihydroquinoline.

2. The method of retarding the deterioration of rubber which comprisesvulcanizing rubber in the presence of 2,2,4-trimethyl-6phenyl-1,2-dihydroquinoline.

3. A vulcanized rubber product resulting from the method set forth inclaim 2.

4. A rubber composition comprising rubber and 2,2,4-trimethyl-6phenyl-1,2-dihydroquinoline.

5. The method of retarding the deterioration of rubber which comprisestreating the rubber with a 1,2-dihydroquinoline of the general formulawherein R is a member of the group consisting of methyl, ethyl, propyl,isopropyl, and butyl radicals, and R is a member of the group consistingof phenyl, tolyl, and xylyl radicals.

6. The method of retarding the deterioration of rubber which comprisesvulcanizing rubber in the presence of a 1,2-dihydroquinoline of thegeneral formula wherein R is a member of the group consisting of methyl,ethyl, propyl, isopropyl, and butyl radicals, and R is a member of thegroup consisting of phenyl, tolyl, and xylyl radicals.

7. A rubber product made by the process of claim 5.

8. A vulcanized rubber product made by the process of claim 6.

RAYMOND F. DUNBROOK. BINGHAM J. HUMPHREY.

